DESCRIPTION: This proposal is concerned with determining the three-dimensional structures of selected compounds with demonstrated or potential usefulness in treatment of AIDS and AIDS associated syndromes and of cancer. The structural results will be used to identify those specific molecular features responsible for anti-AIDS activities, those responsible for anticancer actions and those which cause toxicities. This information will be used for the rational design of new agents which would be expected to be more efficacious, less toxic drugs. Compounds to be studied include: (1) Suramin and suramin analogues. Experiments in this area include structure determinations, modelling of three-dimensional conformations, docking of suramin's three-dimensional conformation to proteins, synthesis and biological testing of new analogues. (2) Glucosidase III inhibitors. (3) New anti-HIV agents from plant sources. (4) Agents useful for PET imagining of HIV-infected cells.